Roman society under the Republic was a cultural mix of Latin, Etruscan, and Greek elements, which is especially visible in the Roman Pantheon. Besides, its political organisation was strongly influenced by the Greek city states of Magna Graecia, with collective and annual magistracies, overseen by a senate. The top magistrates were the two consuls, who had an extensive range of executive, legislative, judicial, military, and religious powers. Whilst there were elections each year, the Republic was not a democracy, but an oligarchy, as a small number of large families (called gentes) monopolised the main magistracies. Roman institutions underwent considerable changes throughout the Republic to adapt to the difficulties it faced, such as the creation of promagistracies to rule its conquered provinces, or the composition of the senate.

At home, the Republic similarly experienced a long streak of social and political crises, which ended in several violent civil wars. At first, the Conflict of the Orders opposed the patricians, the closed oligarchic elite, to the far more numerous plebs, who finally achieved political equality in several steps during the 4th century BC. Later, the vast conquests of the Republic disrupted its society, as the immense influx of slaves they brought enriched the aristocracy, but ruined the peasantry and urban workers. In order to solve this issue, several social reformers, known as the Populares, tried to pass agrarian laws, but the Gracchi brothers, Saturninus, or Clodius Pulcher, were all murdered by their opponents: the Optimates, keepers of the traditional aristocratic order. Mass slavery also caused three Servile Wars; the last of them was led by Spartacus, a skilful gladiator who ravaged Italy and left Rome powerless until his defeat in 71 BC. In this context, the last decades of the Republic were marked by the rise of great generals, who exploited their military conquests and the factional situation in Rome to gain control of the political system. Marius (between 105-86 BC), then Sulla (between 82-78 BC) dominated in turn the Republic; both used extraordinary powers to purge their opponents. These multiple tensions lead to a series of civil wars; the first between the two generals Julius Caesar and Pompey. Despite his victory and appointment as dictator for life, Caesar was murdered in 44 BC. Caesar's heir Octavian and lieutenant Mark Antony defeated Caesar's assassins Brutus and Cassius in 42 BC, but then turned against each other. The final defeat of Mark Antony and his ally Cleopatra at the Battle of Actium in 31 BC, and the Senate's grant of extraordinary powers to Octavian as Augustus in 27 BC – which effectively made him the first Roman emperor – thus ended the Republic.

The Senate agreed to abolish kingship. Most of the king's former functions were transferred to two consuls, who were elected to office for a term of one year. Each consul had the capacity to act as a check on his colleague, if necessary through the same power of veto that the kings had held. If a consul abused his powers in office, he could be prosecuted when his term expired. Brutus and Collatinus became Republican Rome's first consuls. Despite Collatinus' role in the creation of the Republic, he belonged to the same family as the former king, and was forced to abdicate his office and leave Rome. He was replaced as co-consul by Publius Valerius Publicola.[6]

Most modern scholarship describes these events as the quasi-mythological detailing of an aristocratic coup within Tarquin's own family, not a popular revolution. They fit a narrative of a personal vengeance against a tyrant leading to his overthrow, which was common among Greek cities and even theorised by Aristotle.[7][8][9]

The first Roman republican wars were wars of both expansion and defence, aimed at protecting Rome itself from neighbouring cities and nations and establishing its territory in the region.[11] Initially, Rome's immediate neighbours were either Latin towns and villages, or else tribal Sabines from the Apennine hills beyond. One by one Rome defeated both the persistent Sabines and the local cities, both those under Etruscan control and those that had cast off their Etruscan rulers. Rome defeated the Latin cities in the Battle of Lake Regillus in 496, the Battle of Mount Algidus in 458, the Battle of Corbio in 446, the Battle of Aricia, and especially the Battle of the Cremera in 477 wherein it fought against the most important Etruscan city of Veii.[12][13]

By the end of this period, Rome had effectively completed the conquest of their immediate Etruscan and Latin neighbours, and also secured their position against the immediate threat posed by the nearby Apennine hill tribes.[14]

Plebeians and patricians

Beginning with their revolt against Tarquin, and continuing through the early years of the Republic, Rome's patrician aristocrats were the dominant force in politics and society. They initially formed a closed group of about 50 large families, called gentes, who monopolised Rome's magistracies, state priesthoods and senior military posts. The most prominent of these families were the Cornelii,[i] followed by the Aemilii, Claudii, Fabii, and Valerii. The power, privilege and influence of leading families derived from their wealth, in particular from their landholdings, their position as patrons, and their numerous clients.[15]

The vast majority of Roman citizens were commoners of various social degrees. They formed the backbone of Rome's economy, as smallholding farmers, managers, artisans, traders, and tenants. In times of war, they could be summoned for military service. Most had little direct political influence over the Senate's decisions or the laws it passed, including the abolition of the monarchy and the creation of the consular system. During the early Republic, the plebs (or plebeians) emerged as a self-organised, culturally distinct group of commoners, with their own internal hierarchy, laws, customs, and interests.[16]

Plebeians had no access to high religious and civil office,[ii] and could be punished for offences against laws of which they had no knowledge.[17] For the poorest, one of the few effective political tools was their withdrawal of labour and services, in a "secessio plebis"; they would leave the city en masse, and allow their social superiors to fend for themselves. The first such secession occurred in 494, in protest at the abusive treatment of plebeian debtors by the wealthy during a famine.[18] The Senate was compelled to give them direct access to the written civil and religious laws, and to the electoral and political process. To represent their interests, the plebs elected tribunes, who were personally sacrosanct, immune to arbitrary arrest by any magistrate, and had veto power over the passage of legislation.[19]

Celtic invasion of Italy (390–387 BC)

By 390, several Gallic tribes were invading Italy from the north as their culture expanded throughout Europe. The Romans were alerted to this when a particularly warlike tribe, the Senones,[20] invaded two Etruscan towns close to Rome's sphere of influence. These towns, overwhelmed by the enemy's numbers and ferocity, called on Rome for help. The Romans met the Gauls in pitched battle at the Battle of Allia River around 390–387 BC. The Gauls, led by the chieftain Brennus, defeated the Roman army of approximately 15,000 troops, pursued the fleeing Romans back to Rome, and sacked the city before being either driven off or bought off.

From 343 to 341, Rome won two battles against their Samnite neighbours, but were unable to consolidate their gains, due to the outbreak of war with former Latin allies.

In the Latin War (340–338), Rome defeated a coalition of Latins at the battles of Vesuvius and the Trifanum. The Latins submitted to Roman rule.[21]

A Second Samnite War began in 327.[22] The fortunes of the two sides fluctuated, but from 314, Rome was dominant, and offered progressively unfavourable terms for peace. The war ended with Samnite defeat at the Battle of Bovianum (305). By the following year, Rome had annexed most Samnite territory, and began to establish colonies there; but in 298 the Samnites rebelled, and defeated a Roman army, in a Third Samnite War. Following this success they built a coalition of several previous enemies of Rome.[23]

At the Battle of Populonia in 282 Rome finished off the last vestiges of Etruscan power in the region.

Rise of the plebeian nobility

In the 4th century, plebeians gradually obtained political equality with patricians. The starting point was in 400, when the first plebeian consular tribunes were elected; likewise, several subsequent consular colleges counted plebeians (in 399, 396, 388, 383, and 379). The reason behind this sudden gain is unknown,[24] but it was limited as patrician tribunes retained preeminence over their plebeian colleagues.[25] In 385, the former consul and saviour of the besieged Capitol Marcus Manlius Capitolinus is said to have sided with the plebeians, ruined by the Sack and largely indebted to patricians. The issue of debt relief for the plebs remained indeed pressing throughout the century. Livy tells that Capitolinus sold his estate to repay the debt of many of them, and even went over to the plebs, the first patrician to do so. Nevertheless, the growing unrest he had caused led to his trial for seeking kingly power; he was sentenced to death and thrown from the Tarpeian Rock.[26][27]

Between 376 and 367, the tribunes of the plebs Gaius Licinius Stolo and Lucius Sextius Lateranus continued the plebeian agitation and pushed for an ambitious legislation, known as the Leges Liciniae Sextiae. Two of their bills attacked patricians' economic supremacy, by creating legal protection against indebtedness and forbidding excessive use of public land, as the Ager publicus was monopolised by large landowners. The most important bill opened the consulship to plebeians.[28] Other tribunes controlled by the patricians vetoed the bills, but Stolo and Lateranus retaliated by vetoing the elections for five years while being continuously re-elected by the plebs, resulting in a stalemate.[29] In 367, they carried a bill creating the Decemviri sacris faciundis, a college of ten priests, of whom five had to be plebeians, therefore breaking patricians' monopoly on priesthoods. Finally, the resolution of the crisis came from the dictator Camillus, who made a compromise with the tribunes; he agreed to their bills, while they in return consented to the creation of the offices of praetor and curule aediles, both reserved to patricians. Lateranus also became the first plebeian consul in 366; Stolo followed in 361.[30][31][32]

Soon after, plebeians were able to hold both the dictatorship and the censorship, since former consuls normally filled these senior magistracies. The four time consul Gaius Marcius Rutilus became the first plebeian dictator in 356 and censor in 351. In 342, the tribune of the plebs Lucius Genucius passed his Leges Genuciae, which abolished interest on loans, in a renewed effort to tackle indebtedness, required the election of at least one plebeian consul each year, and prohibited a magistrate from holding the same magistracy for the next ten years or two magistracies in the same year.[33][28][34] In 339, the plebeian consul and dictator Quintus Publilius Philo passed three laws extending the powers of the plebeians. His first law followed the Lex Genucia by reserving one censorship to plebeians, the second made plebiscites binding on all citizens (including patricians), and the third stated that the Senate had to give its prior approval to plebiscites before becoming binding on all citizens (the Lex Valeria-Horatia of 449 had placed this approval after the vote).[35] Two years later, Publilius ran for the praetorship, probably in a bid to take the last senior magistracy closed to plebeians, which he won.[36]

During the early republic, senators were chosen by the consuls among their supporters. Shortly before 312, the Lex Ovinia transferred this power to the censors, who could only remove senators for misconduct, thus appointing them for life. This law strongly increased the power of the Senate, which was by now protected from the influence of the consuls and became the central organ of government.[37][38] In 312, following this law, the patrician censor Appius Claudius Caecus appointed many more senators to fill the new limit of 300, including descendants of freedmen, which was deemed scandalous. He also incorporated these freedmen in the rural tribes.[iii][iv] His tribal reforms were nonetheless cancelled by the next censors, Quintus Fabius Maximus and Publius Decius Mus, his political enemies.[39] Caecus also launched a vast construction program, building the first aqueduct (Aqua Appia), and the first Roman road (Via Appia).[40]

In 300, the two tribunes of the plebs Gnaeus and Quintus Ogulnius passed the Lex Ogulnia, which created four plebeian pontiffs, therefore equalling the number of patrician pontiffs, and five plebeian augurs, outnumbering the four patricians in the college.[41] Eventually the Conflict of the Orders ended with the last secession of the plebs in about 287. The details are not known precisely as Livy's books on the period are lost. Debt is once again mentioned by ancient authors, but it seems that the plebs revolted over the distribution of the land conquered on the Samnites.[42] A dictator named Quintus Hortensius was appointed to negotiate with the plebeians, who had retreated to the Janiculum hill, perhaps to dodge the draft in the war against the Lucanians. Hortensius passed the Lex Hortensia which re-enacted the law of 339, making plebiscites binding on all citizens, but also removed the Senate's prior approval to plebiscites. Popular assemblies were by now sovereign; this put an end to the crisis, and to plebeian agitation for 150 years.[43]

These events were a political victory of the wealthy plebeian elite who exploited the economic difficulties of the plebs for their own gain, hence why Stolo, Lateranus, and Genucius bound their bills attacking patricians' political supremacy with debt-relief measures. They had indeed little in common with the mass of plebeians; Stolo was noteworthy fined for having exceeded the limit on land occupation he had fixed in his own law.[44] As a result of the end of the patrician monopoly on senior magistracies, many small patrician gentes faded into history during the 4th and 3rd centuries due to the lack of available positions; the Verginii, Horatii, Menenii, Cloelii all disappear, even the Julii entered a long eclipse. They were replaced by plebeian aristocrats, of whom the most emblematic were the Caecilii Metelli, who received 18 consulships until the end of the Republic; the Domitii, Fulvii, Licinii, Marcii, or Sempronii were as successful. About a dozen remaining patrician gentes and twenty plebeian ones thus formed a new elite, called the nobiles, or Nobilitas.[45]

Pyrrhic War (280–275 BC)

Pyrrhus and his army of 25,500 men (and 20 war elephants) landed in Italy in 280; he was immediately named Strategos Autokrator by the Tarentines. Publius Valerius Laevinus, the consul sent to face him, rejected the king's negotiation offer, as he had more troops and hoped to cut the invasion short. The Romans were nevertheless defeated at Heraclea, as their cavalry were afraid of the elephants of Pyrrhus, who lost a large chunk of his army. Pyrrhus then marched on Rome, but could not take any Roman city on his way; facing the prospect of being flanked by the two consular armies, he moved back to Tarentum. His adviser, the orator Cineas, made a peace offer before the Roman Senate, asking Rome to return the land it took from the Samnites and Lucanians, and liberate the Greek cities under its control. The offer was rejected after Appius Caecus (the old censor of 312) spoke against it in a celebrated speech, which was the earliest recorded by the time of Cicero.[51][52][53] In 279, Pyrrhus met the consuls Publius Decius Mus and Publius Sulpicius Saverrio at the Battle of Asculum, which remained undecided for two days, as the Romans had prepared some special chariots to counter his elephants. Finally, Pyrrhus personally charged into the melee and won the battle, but at the cost of an important part of his troops; he allegedly said "If we are victorious in one more battle with the Romans, we shall be utterly ruined."[54][55][56][v]

He escaped the Italian deadlock by answering a call for help from Syracuse, which tyrant Thoenon was desperately fighting an invasion from Carthage. Pyrrhus could not let them take the whole island as it would have compromised his ambitions in the western Mediterranean and so declared war on them. At first, his Sicilian campaign was an easy triumph; he was welcomed as a liberator in every Greek city on his way, even receiving the title of king (basileus) of Sicily. The Carthaginians lifted the siege of Syracuse before his arrival, but he could not entirely oust them from the island as he failed to take their fortress of Lilybaeum.[57] His harsh rule, especially the murder of Thoenon, whom he did not trust, soon led to a widespread antipathy among the Sicilians; some cities even defected to Carthage. In 275, Pyrrhus left the island before he had to face a full-scale rebellion.[58] He returned to Italy, where his Samnite allies were on the verge of losing the war, despite their earlier victory at the Cranita hills. Pyrrhus again met the Romans at the Battle of Beneventum; this time the consul Manius Dentatus was victorious, and even captured eight elephants. Pyrrhus then withdrew from Italy, but left a garrison in Tarentum, and waged a new campaign in Greece against Antigonos Gonatas. His death in battle at Argos in 272 forced Tarentum to surrender to Rome. Since it was the last independent city of Italy, Rome now dominated the entire Italian peninsula, and won an international military reputation.[59]

Rome and Carthage were initially on friendly terms; Polybius details three treaties between them, the first dating from the first year of the Republic, the second from 348. The last one was an alliance against Pyrrhus.[60][61][62] However, tensions rapidly built on after the departure of the Epirote king. Between 288 and 283, Messena in Sicily was taken by the Mamertines, a band of mercenaries formerly employed by Agathocles. They plundered the surroundings until Hiero II, the new tyrant of Syracuse, defeated them (in either 269 or 265). Carthage could not let him take Messena, as he would have controlled its Strait, and garrisoned the city. In effect under a Carthaginian protectorate, the remaining Mamertines appealed to Rome to regain their independence. Senators were divided on whether to help them or not, as it would have meant war with Carthage, since Sicily was in its sphere of influence (the treaties furthermore forbade the island to Rome), and also Syracuse. A supporter of the war, the consul Appius Claudius Caudex (Caecus' brother) turned to the Tribal Assembly to get a favourable vote, by notably promising booty to voters.[63]

Caudex first secured control of the city with ease. However, Syracuse and Carthage, at war for centuries, made an alliance to counter the invasion and blockaded Messena, but Caudex defeated Hiero and Carthage separately.[64][65] His successor Manius Valerius Corvinus Messalla landed with a strong 40,000 men army that conquered eastern Sicily, which prompted Hiero to shift his allegiance and forge a long lasting alliance with Rome. In 262, the Romans moved to the southern coast and besieged Akragas. In order to raise the siege, Carthage sent reinforcements, including 60 elephants – the first time they used them, but still lost the battle.[66] Nevertheless, as Pyrrhus before, Rome could not take all of Sicily because Carthage's naval superiority prevented them from effectively besieging coastal cities, which could receive supplies from the sea. Using a captured Carthaginian ship as blueprint, Rome therefore launched a massive construction program and built 100 quinqueremes in only two months, perhaps through an assembly line organisation. They also invented a new device, the corvus, a grappling engine which enabled a crew to board on an enemy ship.[67] The consul for 260 Scipio Asina lost the first naval skirmish of the war against Hannibal Gisco at Lipara, but his colleague Gaius Dullius won a great victory at Mylae. He destroyed or captured 44 ships, and was the first Roman to receive a naval triumph, which also included captive Carthaginians for the first time.[68] Although Carthage was victorious on land at Thermae in Sicily, the corvus made Rome invincible on the waters. The consul Lucius Cornelius Scipio (Asina's brother) captured Corsica in 259; his successors won the naval battles of Sulci in 258, Tyndaris in 257, and Cape Ecnomus in 256.[69]

Diagram of a corvus.

In order to haste the end of the war, the consuls for 256 decided to carry the operations to Africa, on Carthage's homeland. The consul Marcus Atilius Regulus landed on the Cap Bon peninsula with about 18,000 soldiers. He captured the city of Aspis, then repulsed Carthage's counter-attack at Adys, and took Tunis. The Carthaginians supposedly sued him for peace, but his conditions were so harsh that they continued the war instead. They hired Spartan mercenaries, led by Xanthippus, to command their troops.[70] In 255, the Spartan general marched on Regulus, still encamped at Tunis, who accepted the battle to avoid sharing the glory with his successor. However, the flat land near Tunis favoured the Punic elephants, which crushed the Roman infantry on the Bagradas plain; only 2,000 soldiers escaped, and Regulus was captured. The consuls for 255 nonetheless won a new sounding naval victory at Cape Hermaeum, where they captured 114 warships. This success was spoilt by a storm that annihilated the victorious navy: 184 ships on 264 sank, 25.000 soldiers and 75.000 rowers drowned. The corvus considerably hindered ships' navigation, and made them vulnerable during tempest. It was abandoned after another similar catastrophe took place in 253 (150 ships sank with their crew). These disasters prevented any significant campaign between 254 and 252.[71]

Hostilities in Sicily resumed in 252, with the taking of Thermae by Rome. Carthage countered the following year, by besieging Lucius Caecilius Metellus, who held Panormos (now Palermo). The consul had dug trenches to counter the elephants, which once hurt by missiles turned back on their own army, resulting in a great victory for Metellus, who exhibited some captured beasts in the Circus. Rome then besieged the last Carthaginian strongholds in Sicily, Lilybaeum and Drepana, but these cities were impregnable by land. Publius Claudius Pulcher, the consul of 249, recklessly tried to take the latter from the sea, but he suffered a terrible defeat; his colleague Lucius Junius Pullus likewise lost his fleet off Lilybaeum. Without corvus, Roman warships had lost their advantage. By now, both sides were drained and could not undertake large scale operations; Roman citizenry had indeed been reduced by 17% in 20 years. The only military activity during this period was the landing in Sicily of Hamilcar Barca in 247, who harassed the Romans with a mercenary army from a citadel he built on Mt. Eryx.[73]

Finally, unable to take the Punic fortresses in Sicily, Rome tried to win the decision at sea and built a new navy, thanks to a forced borrowing on the rich. In 242, the 200 quinqueremes of the consul Gaius Lutatius Catulus blockaded Drepana. The rescue fleet from Carthage arrived the next year, but was largely undermanned and soundly defeated by Catulus. Exhausted and unable to bring supplies to Sicily, Carthage sued for peace. Catulus and Hamilcar negotiated a treaty, which was somewhat lenient to Carthage, but the Roman people rejected it and imposed harsher terms: Carthage had to pay 1000 talents immediately and 2200 over ten years, and evacuate Sicily. The fine was so high that Carthage could not pay Hamilcar's mercenaries, who had been shipped back to Africa. They revolted during the Mercenary War, which Carthage had enormous difficulties to suppress. Meanwhile, Rome took advantage of a similar revolt in Sardinia to seize the island from Carthage, in violation of the peace treaty. This stab-in-the-back led to permanent bitterness in Carthage, and revanchism.[74]

After its victory, the Republic shifted its attention to its northern border as the Insubres and Boii were threatening Italy.[75] Meanwhile, Carthage compensated the loss of Sicily and Sardinia with the conquest of Southern Hispania (up to Salamanca), and its rich silver mines.[76] This enterprise was the work of the Barcid family, headed by Hamilcar, the former commander in Sicily. Hamilcar nonetheless died against the Oretani in 228; his son-in-law Hasdrubal the Fair – the founder of Carthago Nova – and his three sons Hannibal, Hasdrubal, and Mago, succeeded him.[77] This rapid expansion worried Rome, which concluded a treaty with Hasdrubal in 226, stating that Carthage could not cross the Ebro river.[78] However, the city of Saguntum, located in the south of the Ebro, appealed to Rome in 220 to act as arbitrator during a stasis. Hannibal dismissed Roman rights on the city, and took it in 219. At Rome, the Cornelii and the Aemilii considered the capture of Saguntum a casus belli,[79] and won the debate against Fabius Maximus Verrucosus, who wanted to negotiate. An embassy carrying an ultimatum was sent to Carthage, asking its senate to condemn Hannibal's deeds. The Carthaginian refusal started the Second Punic War.

Initially, the plan of the Republic was to carry war outside Italy, by sending the consuls Publius Cornelius Scipio to Hispania, and Sempronius Longus to Africa, while their naval superiority prevented Carthage from attacking from the sea. This plan was thwarted by Hannibal's bold move to Italy. In May 218, he indeed crossed the Ebro with a large army of about 46,000 soldiers and 37 elephants.[80] He passed in Gaul, crossed the Rhone, then the Alps, possibly through the Col de Clapier (2,491 meters high). This famous exploit cost him half of his troops,[81] but he could now rely on the Boii, still at war with Rome. Publius Scipio, who had failed to block Hannibal on the Rhone, sent his elder brother Gnaeus with the main part of his army in Hispania according to the initial plan, and went back to Italy with the rest to resist Hannibal in Italy, but he was defeated and wounded near Pavia.

Hannibal then marched south and won three outstanding victories. The first one was on the banks of the Trebia in December 218, where he defeated the other consul Sempronius Longus thanks to his brother Mago, who had concealed some elite troops behind the legions and attacked them from the rear once fighting Hannibal. More than half of the Roman army was lost. Hannibal then ravaged the country around Arretium to lure the new consul Gaius Flaminius into a trap, at the Lake Trasimene. He had hidden his troops in the hills surrounding the lake and attacked Flaminius when he was cornered on the shore. This clever ambush resulted in the death of the consul and the complete destruction his army of 30,000 men. In 216, the new consuls Aemilius Paullus and Terentius Varro mustered the biggest army possible, with eight legions (more than 80,000 soldiers) – twice as many as the Punic army – and confronted Hannibal, who was encamped at Cannae, in Apulia. Despite his numerical disadvantage, Hannibal used his heavier cavalry to rout the Roman wings and envelope their infantry, whom he annihilated. In terms of casualties, the Battle of Cannae was the worst defeat in the history of Rome: only 14,500 soldiers escaped; Paullus was killed as well as well as 80 senators.[82] Soon after, the Boii ambushed the army of the consul-elect for 215, Postumius Albinus, who died with all his army of 25,000 men in the Forest of Litana.

A quarter shekel of Carthage, perhaps minted in Spain. The obverse may depicts Hannibal under the traits of young Melqart. The reverse features one of his famous war elephants.[83]

These disasters triggered a wave of defection among Roman allies, with the rebellions of the Samnites, Oscans, Lucanians, and the Greek cities of Southern Italy. In Macedonia, Philip V also made an alliance with Hannibal in order to take Illyria and the area around Epidamnus, occupied by Rome. His attack on Apollonia started the First Macedonian War. In 215, Hiero II of Syracuse died of old age, and his young grandson Hieronymus broke the long alliance with Rome to side with Carthage. At this desperate point, the aggressive strategy against Hannibal advocated by the Scipii was abandoned in favour of delaying tactics that avoided direct confrontation with him. Its main proponents were the consuls Fabius Maximus Verrucosus, nicknamed Cunctator ("the delayer"), Claudius Marcellus, and Fulvius Flaccus. The "Fabian Strategy" favoured a slow reconquest of the lost territories, since Hannibal could not be everywhere to defend them. Although he remained invincible on the battlefield, defeating all the Roman armies on his way, he could not prevent Claudius Marcellus from taking Syracuse in 212 after a long siege, nor the fall of his bases of Capua and Tarentum in 211 and 209. However, in 208 the consuls Claudius Marcellus and Quinctius Crispinus were ambushed and killed near Venusia.

In Hispania, the situation was overall much better for Rome. This theatre was mostly commanded by the brothers Publius and Gnaeus Scipio, who won the battles of Cissa in 218, soon after Hannibal's departure, and Dertosa against his brother Hasdrubal in 215, which enabled them to conquer the eastern coast of Hispania. In 211 however, Hasdrubal and Mago Barca successfully returned the Celtiberian tribes that supported the Scipii, and attacked them simultaneously at the Battle of the Upper Baetis, in which the Scipii brothers died. Publius' son, the future Scipio Africanus, was then elected with a special proconsulship to lead the Hispanic campaign. He soon showed outstanding skills as commander, by winning a series of battles with ingenious tactics. In 209, he thus took Carthago Nova, the main Punic base in Hispania, then defeated Hasdrubal at the Battle of Baecula (208). After his defeat, Hasdrubal was ordered by Carthage to move to Italy. Since he could not use ships, he followed the same route as his brother through the Alps, but this time the surprise effect was gone. The consuls Livius Salinator and Claudius Nero were awaiting him and won the Battle of the Metaurus, where Hasdrubal died; it was the turning point of the war. The attrition campaign had indeed worked well: Hannibal's troops were now depleted; he only had one elephant left (named Surus) and retreated to Bruttium, on the defensive. In Greece, Rome contained Philip V without devoting too much forces, by setting an alliance with the Aetolian League, Sparta, and Pergamon, which also prevented Philip from aiding Hannibal. The war resulted in a stalemate, with the Treaty of Phoenice signed in 205.

In Hispania, Scipio continued his triumphal campaign at the battles of Carmona in 207, and Ilipa (now Seville) in 206, which ended the Punic threat on the peninsula. Elected consul in 205, he convinced the senate to cancel the Fabian Strategy, and instead to invade Africa by using the support of the Numidian king Massinissa, who had defected to Rome. Scipio landed in Africa in 204. He took Utica, then won the Battle of the Great Plains, which prompted Carthage to recall Hannibal from Italy and open peace negotiations with Rome. The talks nevertheless failed because Scipio wanted to impose harsher terms on Carthage, in order to avoid it from rising again as a threat to Rome. Hannibal was therefore sent to face Scipio at Zama. Scipio could now use the heavy Numidian cavalry of Massinissa – which had hitherto been so successful against Rome – to rout the Punic wings, then flank the infantry, as Hannibal had done at Cannae. Defeated for the first time, Hannibal convinced the Carthaginian senate to pay the war indemnity, which was even harsher than that of 241: 10,000 talents in 50 instalments. Carthage furthermore had to give up all its elephants, all its fleet but ten triremes, all its possessions outside its core territory in Africa (what is now Tunisia), and could not declare war without the authorisation of Rome. In effect, Carthage was condemned to be a minor power, while Rome recovered from a desperate situation to dominate the Western Mediterranean.

Roman supremacy in the Greek East (200–188 BC)

Macedonian Wars

Macedonia, Greece and Asia at the outbreak of the Second Macedonian War, 200 BC.

Rome's preoccupation with its war with Carthage provided an opportunity for Philip V of the kingdom of Macedonia, located in the north of the Greek peninsula, to attempt to extend his power westward. Philip sent ambassadors to Hannibal's camp in Italy, to negotiate an alliance as common enemies of Rome.[84][85] However, Rome discovered the agreement when Philip's emissaries were captured by a Roman fleet.[84] The First Macedonian War saw the Romans involved directly in only limited land operations, but they ultimately achieved their objective of pre-occupying Philip and preventing him from aiding Hannibal.

The past century had seen the Greek world dominated by the three primary successor kingdoms of Alexander the Great's empire: Ptolemaic Egypt, Macedonia and the Seleucid Empire. In 202, internal problems led to a weakening of Egypt's position, thereby disrupting the power balance among the successor states. Macedonia and the Seleucid Empire agreed to an alliance to conquer and divide Egypt.[86] Fearing this increasingly unstable situation, several small Greek kingdoms sent delegations to Rome to seek an alliance.[87] The delegation succeeded, even though prior Greek attempts to involve Rome in Greek affairs had been met with Roman apathy. Our primary source about these events, the surviving works of Polybius, do not state Rome's reason for getting involved. Rome gave Philip an ultimatum to cease his campaigns against Rome's new Greek allies. Doubting Rome's strength (a reasonable doubt, given Rome's performance in the First Macedonian War) Philip ignored the request, and Rome sent an army of Romans and Greek allies, beginning the Second Macedonian War.[88] Despite his recent successes against the Greeks and earlier successes against Rome, Philip's army buckled under the pressure from the Roman-Greek army. In 197, the Romans decisively defeated Philip at the Battle of Cynoscephalae, and Philip was forced to give up his recent Greek conquests.[89] The Romans declared the "Peace of the Greeks", believing that Philip's defeat now meant that Greece would be stable. They pulled out of Greece entirely, maintaining minimal contacts with their Greek allies.[90]

With Egypt and Macedonia weakened, the Seleucid Empire made increasingly aggressive and successful attempts to conquer the entire Greek world.[91] Now not only Rome's allies against Philip, but even Philip himself, sought a Roman alliance against the Seleucids.[92] The situation was made worse by the fact that Hannibal was now a chief military advisor to the Seleucid emperor, and the two were believed to be planning an outright conquest not just of Greece, but of Rome itself.[93] The Seleucids were much stronger than the Macedonians had ever been, because they controlled much of the former Persian Empire, and by now had almost entirely reassembled Alexander the Great's former empire.[93]

Fearing the worst, the Romans began a major mobilization, all but pulling out of recently pacified Spain and Gaul.[93] They even established a major garrison in Sicily in case the Seleucids ever got to Italy.[93] This fear was shared by Rome's Greek allies, who had largely ignored Rome in the years after the Second Macedonian War, but now followed Rome again for the first time since that war.[93] A major Roman-Greek force was mobilized under the command of the great hero of the Second Punic War, Scipio Africanus, and set out for Greece, beginning the Roman-Syrian War. After initial fighting that revealed serious Seleucid weaknesses, the Seleucids tried to turn the Roman strength against them at the Battle of Thermopylae (as they believed the 300 Spartans had done centuries earlier).[92] Like the Spartans, the Seleucids lost the battle, and were forced to evacuate Greece.[92] The Romans pursued the Seleucids by crossing the Hellespont, which marked the first time a Roman army had ever entered Asia.[92] The decisive engagement was fought at the Battle of Magnesia, resulting in a complete Roman victory.[92][95] The Seleucids sued for peace, and Rome forced them to give up their recent Greek conquests. Although they still controlled a great deal of territory, this defeat marked the decline of their empire, as they were to begin facing increasingly aggressive subjects in the east (the Parthians) and the west (the Greeks). Their empire disintegrated into a rump over the course of the next century, when it was eclipsed by Pontus. Following Magnesia, Rome again withdrew from Greece, assuming (or hoping) that the lack of a major Greek power would ensure a stable peace. In fact, it did the opposite.[96]

Conquest of Greece (172–146 BC)

In 179 Philip died.[97] His talented and ambitious son, Perseus, took the throne and showed a renewed interest in conquering Greece.[98] With her Greek allies facing a major new threat, Rome declared war on Macedonia again, starting the Third Macedonian War. Perseus initially had some success against the Romans. However, Rome responded by sending a stronger army. This second consular army decisively defeated the Macedonians at the Battle of Pydna in 168[97][99] and the Macedonians duly capitulated, ending the war.[100]

Convinced now that the Greeks (and therefore the rest of the region) would not have peace if left alone, Rome decided to establish its first permanent foothold in the Greek world, and divided the Kingdom of Macedonia into four client republics. Yet, Macedonian agitation continued. The Fourth Macedonian War, 150 to 148 BC, was fought against a Macedonian pretender to the throne who was again destabilizing Greece by trying to re-establish the old kingdom. The Romans swiftly defeated the Macedonians at the Second battle of Pydna.

The Achaean League chose this moment to fight Rome but was swiftly defeated. In 146 (the same year as the destruction of Carthage), Corinth was besieged and destroyed, which led to the league's surrender.[101] After nearly a century of constant crisis management in Greece, which always led back to internal instability and war when she withdrew, Rome decided to divide Macedonia into two new Roman provinces, Achaea and Macedonia.

Third Punic War (149–146 BC)

Carthage never recovered militarily after the Second Punic War,[102] but quickly did so economically and the Third Punic War that followed was in reality a simple punitive mission after the neighbouring Numidians allied to Rome robbed/attacked Carthaginian merchants. Treaties had forbidden any war with Roman allies, and defence against robbing/pirates was considered as "war action": Rome decided to annihilate the city of Carthage.[103] Carthage was almost defenceless, and submitted when besieged.[104] However, the Romans demanded complete surrender and removal of the city into the (desert) inland far off any coastal or harbour region, and the Carthaginians refused. The city was besieged, stormed, and completely destroyed.

Ultimately, all of Carthage's North African and Iberian territories were acquired by Rome. Note that "Carthage" was not an 'empire', but a league of Punic colonies (port cities in the western Mediterranean) like the 1st and 2nd Athenian ("Attic") leagues, under leadership of Carthage. Punic Carthage was gone, but the other Punic cities in the western Mediterranean flourished under Roman rule.

Social troubles and first civil war (146–60 BC)

Rome's rapid expansion destabilised its social organisation and triggered unrest in its core territory, which ultimately led to several revolts and a civil war. The period is marked by the rise of strong men (Marius, then Sulla, Pompey, and to a lesser extent Crassus), who exploited their military successes to control the political system.

In this context, Tiberius Gracchus was elected tribune in 133. He attempted to enact a law which would have limited the amount of land that any individual could own. The aristocrats, who stood to lose an enormous amount of money, were bitterly opposed to this proposal. Tiberius submitted this law to the Plebeian Council, but the law was vetoed by a tribune named Marcus Octavius. Tiberius then used the Plebeian Council to impeach Octavius. The theory, that a representative of the people ceases to be one when he acts against the wishes of the people, was counter to Roman constitutional theory. If carried to its logical end, this theory would remove all constitutional restraints on the popular will, and put the state under the absolute control of a temporary popular majority.[105] His law was enacted, but Tiberius was murdered with 300 of his associates[106] when he stood for reelection to the tribunate.

Tiberius' brother Gaius was elected tribune in 123. Gaius Gracchus' ultimate goal was to weaken the senate and to strengthen the democratic forces.[107] In the past, for example, the senate would eliminate political rivals either by establishing special judicial commissions or by passing a
senatus consultum ultimum ("ultimate decree of the senate"). Both devices would allow the Senate to bypass the ordinary due process rights that all citizens had. Gaius outlawed the judicial commissions, and declared the senatus consultum ultimum to be unconstitutional. Gaius then proposed a law which would grant citizenship rights to Rome's Italian allies. This last proposal was not popular with the plebeians and he lost much of his support.[108] He stood for election to a third term in 121, but was defeated and then murdered by representatives of the senate with 3,000 of his supporters on Capitoline Hill in Rome.[106]

In 121, the province of Gallia Narbonensis was established after the victory of Quintus Fabius Maximus over a coalition of Arverni and Allobroges in southern Gaul in 123. The city of Narbo was founded there in 118 by Lucius Licinius Crassus.

Rise of Marius

The Jugurthine War of 111–104 was fought between Rome and Jugurtha of the North African kingdom of Numidia. It constituted the final Roman pacification of Northern Africa,[109] after which Rome largely ceased expansion on the continent after reaching natural barriers of desert and mountain. Following Jugurtha's usurpation of the throne of Numidia,[110] a loyal ally of Rome since the Punic Wars,[111] Rome felt compelled to intervene. Jugurtha impudently bribed the Romans into accepting his usurpation. Jugurtha was finally captured not in battle but by treachery.

In 118, King Micipsa of Numidia (current-day Algeria and Tunisia) died. He was succeeded by two legitimate sons, Adherbal and Hiempsal, and an illegitimate son, Jugurtha. Micipsa divided his kingdom between these three sons. Jugurtha, however, turned on his brothers, killing Hiempsal and driving Adherbal out of Numidia. Adherbal fled to Rome for assistance, and initially Rome mediated a division of the country between the two brothers. Eventually, Jugurtha renewed his offensive, leading to a long and inconclusive war with Rome. He also bribed several Roman commanders, and at least two tribunes, before and during the war. His nemesis, Gaius Marius, a legate from a virtually unknown provincial family, returned from the war in Numidia and was elected consul in 107 over the objections of the aristocratic senators. Marius invaded Numidia and brought the war to a quick end, capturing Jugurtha in the process. The apparent incompetence of the Senate, and the brilliance of Marius, had been put on full display.[113] The populares party took full advantage of this opportunity by allying itself with Marius.

In 91 the Social War broke out between Rome and its former allies in Italy when the allies complained that they shared the risk of Rome's military campaigns, but not its rewards. Although they lost militarily, the allies achieved their objectives with legal proclamations which granted citizenship to more than 500,000 Italians.

The internal unrest reached its most serious state, however, in the two civil wars that were caused by the clash between generals Gaius Marius and Lucius Cornelius Sulla starting from 88. In the Battle of the Colline Gate[117] at the very door of the city of Rome, a Roman army under Sulla bested an army of the Marius supporters and entered the city. Sulla's actions marked a watershed in the willingness of Roman troops to wage war against one another that was to pave the way for the wars which ultimately overthrew the Republic, and caused the founding of the Roman Empire.

Several years later, in 88, a Roman army was sent to put down an emerging Asian power, king Mithridates of Pontus. The army, however, was not defeated and won. One of Marius' old quaestors, Lucius Cornelius Sulla, had been elected consul for the year, and was ordered by the senate to assume command of the war against Mithridates. Marius, a member of the "populares" party, had a tribune revoke Sulla's command of the war against Mithridates. Sulla, a member of the aristocratic ("optimates") party, brought his army back to Italy and marched on Rome. Sulla was so angry at Marius' tribune that he passed a law intended to permanently weaken the tribunate.[118] He then returned to his war against Mithridates. With Sulla gone, the populares under Marius and Lucius Cornelius Cinna soon took control of the city.

During the period in which the populares party controlled the city, they flouted convention by re-electing Marius consul several times without observing the customary ten-year interval between offices.[119] They also transgressed the established oligarchy by advancing unelected individuals to magisterial office, and by substituting magisterial edicts for popular legislation. Sulla soon made peace with Mithridates. In 83, he returned to Rome, overcame all resistance, and recaptured the city. Sulla and his supporters then slaughtered most of Marius' supporters. Sulla, having observed the violent results of radical popular reforms, was naturally conservative. As such, he sought to strengthen the aristocracy, and by extension the senate.[120] Sulla made himself dictator, passed a series of constitutional reforms, resigned the dictatorship, and served one last term as consul. He died in 78.

Mithridates the Great was the ruler of Pontus,[124] a large kingdom in Asia Minor (modern Turkey), from 120 to 63. Mithridates antagonised Rome by seeking to expand his kingdom,[124] and Rome for its part seemed equally eager for war and the spoils and prestige that it might bring.[124][125] In 88, Mithridates ordered the killing of a majority of the 80,000 Romans living in his kingdom.[126] The massacre was the official reason given for the commencement of hostilities in the First Mithridatic War. The Roman general Lucius Cornelius Sulla forced Mithridates out of Greece proper, but then had to return to Italy to answer the internal threat posed by his rival, Gaius Marius. A peace was made between Rome and Pontus, but this proved only a temporary lull.

The Mediterranean had at this time fallen into the hands of pirates,[128] largely from Cilicia.[129] The pirates not only strangled shipping lanes but also plundered many cities on the coasts of Greece and Asia. Pompey was nominated as commander of a special naval task force to campaign against the pirates.[127][128] It took Pompey just forty days to clear the western portion of the sea of pirates and restore communication between Iberia (Spain), Africa, and Italy.

In 77, the senate sent one of Sulla's former lieutenants, Gnaeus Pompeius Magnus ("Pompey the Great"), to put down an uprising in Hispania. By 71, Pompey returned to Rome after having completed his mission. Around the same time, another of Sulla's former lieutenants, Marcus Licinius Crassus, had just put down the Spartacus-led gladiator/slave revolt in Italy. Upon their return, Pompey and Crassus found the populares party fiercely attacking Sulla's constitution.[130] They attempted to forge an agreement with the populares party. If both Pompey and Crassus were elected consul in 70, they would dismantle the more obnoxious components of Sulla's constitution. The two were soon elected, and quickly dismantled most of Sulla's constitution.[131]

Around 66, a movement to use constitutional, or at least peaceful, means to address the plight of various classes began.[132] After several failures, the movement's leaders decided to use any means that were necessary to accomplish their goals. The movement coalesced under an aristocrat named Lucius Sergius Catilina. The movement was based in the town of Faesulae, which was not a natural hotbed of agrarian agitation.[133] The rural malcontents were to advance on Rome,[134] and be aided by an uprising within the city. After assassinating the consuls and most of the senators, Catiline would be free to enact his reforms. The conspiracy was set in motion in 63. The consul for the year, Marcus Tullius Cicero, intercepted messages that Catiline had sent in an attempt to recruit more members. As a result, the top conspirators in Rome (including at least one former consul) were executed by authorisation (of dubious constitutionality) of the senate, and the planned uprising was disrupted. Cicero then sent an army, which cut Catiline's forces to pieces.

The most important result of the Catilinarian conspiracy was that the populares party became discredited. The prior 70 years had witnessed a gradual erosion in senatorial powers. The violent nature of the conspiracy, in conjunction with the senate's skill in disrupting it, did a great deal to repair the senate's image.[134]

In 62, Pompey returned victorious from Asia. The Senate, elated by its successes against Catiline, refused to ratify the arrangements that Pompey had made. Pompey, in effect, became powerless. Thus, when Julius Caesar returned from a governorship in Spain in 61, he found it easy to make an arrangement with Pompey. Caesar and Pompey, along with Crassus, established a private agreement, now known as the First Triumvirate. Under the agreement, Pompey's arrangements would be ratified. Caesar would be elected consul in 59, and would then serve as governor of Gaul for five years. Crassus was promised a future consulship.[135]

Caesar became consul in 59. His colleague, Marcus Calpurnius Bibulus, was an extreme aristocrat. Caesar submitted the laws that he had promised Pompey to the assemblies. Bibulus attempted to obstruct the enactment of these laws, and so Caesar used violent means to ensure their passage.[135] Caesar was then made governor of three provinces. He facilitated the election of the former patrician Publius Clodius Pulcher to the tribunate for 58. Clodius set about depriving Caesar's senatorial enemies of two of their more obstinate leaders in Cato and Cicero. Clodius was a bitter opponent of Cicero because Cicero had testified against him in a sacrilege case. Clodius attempted to try Cicero for executing citizens without a trial during the Catiline conspiracy, resulting in Cicero going into self-imposed exile and his house in Rome being burnt down. Clodius also passed a bill that forced Cato to lead the invasion of Cyprus which would keep him away from Rome for some years. Clodius also passed a law to expand the previous partial grain subsidy to a fully free grain dole for citizens.[137]

During his term as praetor in the Iberian Peninsula (modern Portugal and Spain), Pompey's contemporary Julius Caesar defeated two local tribes in battle.[138] After his term as consul in 59, he was appointed to a five-year term as the proconsular Governor of Cisalpine Gaul (part of current northern Italy), Transalpine Gaul (current southern France) and Illyria (part of the modern Balkans).[138][139] Not content with an idle governorship, Caesar strove to find reason to invade Gaul (modern France and Belgium), which would give him the dramatic military success he sought. When two local tribes began to migrate on a route that would take them near (not into) the Roman province of Transalpine Gaul, Caesar had the barely sufficient excuse he needed for his Gallic Wars, fought between 58 and 49.

Caesar defeated large armies at major battles 58 and 57. In 55 and 54 he made two expeditions into Britain, the first Roman to do so. Caesar then defeated a union of Gauls at the Battle of Alesia,[140] completing the Roman conquest of Transalpine Gaul. By 50, all of Gaul lay in Roman hands.

In 53, Crassus launched a Roman invasion of the Parthian Empire (modern Iraq and Iran). After initial successes,[141] he marched his army deep into the desert;[142] but here his army was cut off deep in enemy territory, surrounded and slaughtered at the Battle of Carrhae in which Crassus himself perished. The death of Crassus removed some of the balance in the Triumvirate and, consequently, Caesar and Pompey began to move apart. While Caesar was fighting in Gaul, Pompey proceeded with a legislative agenda for Rome that revealed that he was at best ambivalent towards Caesar[143] and perhaps now covertly allied with Caesar's political enemies. In 51, some Roman senators demanded that Caesar not be permitted to stand for consul unless he turned over control of his armies to the state, which would have left Caesar defenceless before his enemies. Caesar chose civil war over laying down his command and facing trial.

Clodius formed armed gangs that terrorised the city and eventually began to attack Pompey's followers, who in response funded counter-gangs formed by Titus Annius Milo. The political alliance of the triumvirate was crumbling. Domitius Ahenobarbus ran for the consulship in 55 promising to take Caesar's command from him. Eventually, the triumvirate was renewed at Lucca. Pompey and Crassus were promised the consulship in 55, and Caesar's term as governor was extended for five years. Crassus led an ill-fated expedition with legions led by his son, Caesar's lieutenant, against the Kingdom of Parthia. This resulted in his defeat and death at the Battle of Carrhae. Finally, Pompey's wife, Julia, who was Caesar's daughter, died in childbirth. This event severed the last remaining bond between Pompey and Caesar.

Beginning in the summer of 54, a wave of political corruption and violence swept Rome.[144] This chaos reached a climax in January of 52 BC, when Clodius was murdered in a gang war by Milo.

On 1 January 49, an agent of Caesar presented an ultimatum to the senate. The ultimatum was rejected, and the senate then passed a resolution which declared that if Caesar did not lay down his arms by July of that year, he would be considered an enemy of the Republic.[145] Meanwhile, the senators adopted Pompey as their new champion against Caesar. On 7 January of 49, the senate passed a senatus consultum ultimum, which vested Pompey with dictatorial powers. Pompey's army, however, was composed largely of untested conscripts. On 10 January, Caesar crossed the Rubicon with his veteran army (in violation of Roman laws) and marched towards Rome. Caesar's rapid advance forced Pompey, the consuls and the senate to abandon Rome for Greece. Caesar entered the city unopposed.

By the spring of 49, the hardened legions of Caesar crossed the river Rubicon, the legal boundary of Roman Italy beyond which no commander might bring his army, and swept down the Italian peninsula towards Rome, while Pompey ordered the abandonment of Rome. Afterwards Caesar turned his attention to the Pompeian stronghold of Hispania (modern Spain)[146] but decided to tackle Pompey himself in Greece.[147] Pompey initially defeated Caesar, but failed to follow up on the victory, and was decisively defeated at the Battle of Pharsalus in 48,[148] despite outnumbering Caesar's forces two to one, albeit with inferior quality troops.[149] Pompey fled again, this time to Egypt, where he was murdered.

Pompey's death did not end the civil war, as Caesar's many enemies fought on. In 46 Caesar lost perhaps as much as a third of his army, but ultimately came back to defeat the Pompeian army of Metellus Scipio in the Battle of Thapsus, after which the Pompeians retreated yet again to Hispania. Caesar then defeated the combined Pompeian forces at the Battle of Munda.

With Pompey defeated and order restored, Caesar wanted to achieve undisputed control over the government. The powers which he gave himself were later assumed by his imperial successors.[150] His assumption of these powers decreased the authority of Rome's other political institutions.

Caesar held both the dictatorship and the tribunate, and alternated between the consulship and the proconsulship.[150] In 48, Caesar was given permanent tribunician powers. This made his person sacrosanct, gave him the power to veto the senate, and allowed him to dominate the Plebeian Council. In 46, Caesar was given censorial powers,[151] which he used to fill the senate with his own partisans. Caesar then raised the membership of the Senate to 900.[152] This robbed the senatorial aristocracy of its prestige, and made it increasingly subservient to him. While the assemblies continued to meet, he submitted all candidates to the assemblies for election, and all bills to the assemblies for enactment. Thus, the assemblies became powerless and were unable to oppose him.[153]

Near the end of his life, Caesar began to prepare for a war against the Parthian Empire. Since his absence from Rome would limit his ability to install his own consuls, he passed a law before his death which allowed him to appoint all magistrates, and later all consuls and tribunes. This transformed the magistrates from representatives of the people to representatives of the dictator.[152]

Caesar was now the primary figure of the Roman state, enforcing and entrenching his powers. His enemies feared that he had ambitions to become an autocratic ruler. Arguing that the Roman Republic was in danger, a group of senators hatched a conspiracy and assassinated Caesar at a meeting of the Senate in March 44.[154]

Caesar was assassinated on 15 March 44. The assassination was led by Gaius Cassius and Marcus Brutus. Most of the conspirators were senators, who had a variety of economic, political, or personal motivations for carrying out the assassination. Many were afraid that Caesar would soon resurrect the monarchy and declare himself king. Others feared loss of property or prestige as Caesar carried out his land reforms in favor of the landless classes. Virtually all the conspirators fled the city after Caesar's death in fear of retaliation. The civil war that followed destroyed what was left of the Republic.[155]

Second Triumvirate

Mark Antony, Caesar's lieutenant, condemned Caesar's assassination, and war broke out between the two factions. Antony was denounced as a public enemy, and Caesar's adopted son and chosen heir, Gaius Octavianus, was entrusted with the command of the war against him. At the Battle of Mutina Mark Antony was defeated by the consuls Hirtius and Pansa, who were both killed.

After the assassination, Marcus Antonius (Mark Antony) formed an alliance with Caesar's adopted son and great-nephew, Gaius Octavianus (Octavian). Along with Marcus Lepidus, they formed an alliance known as the Second Triumvirate.[158] They held powers that were nearly identical to the powers that Caesar had held under his constitution. As such, the Senate and assemblies remained powerless, even after Caesar had been assassinated. The conspirators were then defeated at the Battle of Philippi in 42. Eventually, however, Antony and Octavian fought against each other in one last battle. Antony was defeated in the naval Battle of Actium in 31, and he committed suicide with his lover, Cleopatra. In 29, Octavian returned to Rome as the unchallenged master of the Empire and later accepted the title of Augustus ("Exalted One"). He was convinced that only a single strong ruler could restore order in Rome.

However, civil war flared again when the Second Triumvirate of Octavian, Lepidus and Mark Antony failed. The ambitious Octavian built a power base of patronage and then launched a campaign against Mark Antony.[154] At the naval Battle of Actium in 31 off the coast of Greece, Octavian decisively defeated Antony and Cleopatra of Ptolemaic Egypt. Octavian was granted a series of special powers including sole "imperium" within the city of Rome, permanent consular powers and credit for every Roman military victory, since all future generals were assumed to be acting under his command. In 27 Octavian was granted the use of the names "Augustus", indicating his primary status above all other Romans, "Princeps", which he used to refer to himself as in public, and he adopted the title "Imperator Caesar" making him the first Roman Emperor.[159]